Steam boiler



l. HARTER STEAM BOILER Dec. 4, i928.

INVENTOR.

ATTORNEYS.

2 Sheets-Sheet Filed March 30, 1922 Dec. 1, i928.

I. HARTER STEAM BOILER Filed March 30, 1922 2 Sheets-Sheet 2 INVENTOR@indented @en d, i928,

` natale ESM@ MEER, 0F BONGAN HMS, NEW YGRK, ASSGN T0. THE BMCOCK d5WIEL- GQX COMANY, 0F DBAYGNNJE, NEW JERSEY, A COBFEATIEON DE' NEWJERSEY.

ernaar notarse.

.application led March 3G, 1922. Serial No. dl.

lli/ly. present invention relates to water-tube boilers in which someorv all of the tufbesA are subjected to an intense heat. Under suchconditions, particularly the tubes adjacent-- t9 provide a constructionwhich will miniinize this .diculty M i invention will best be understoodfrom lo the ollowing description and the appendedV drawing, in whichFig. 1 is a partial sectional elevation of a water-tubeboiler which lhave chosen for purposes of illustration; Fig.` 2 is an enlargement ofa. portion of one oit the.

M headers shown in Fig. 1, with the end of the tube expanded therein,Fign is an enlarged cross-section through one of the headers and the endof a tube inserted'therein, showing a v step in the expansion of thetube into the 20 header, and F ig. 4 is a fragmentary section through aportion oit' a header showing one of the tubes of the lowermost row andtube of other rows expanded therein. I

Like reference characters reiter to like parts in the'several views. l A

rlhe illustrative form 'of boiler has uptake headers 10 and downtakeheaders 11 connectedbyhorizontall inclined water tubes' arrangedin rowsin t e usual manner. The lowerm'st row 12 'is exposed' for its entirelength to the direct radiantheat ofthe 'furnace, while the row. 1,3above' it is protected from such heat toa degree by the row of tubes12'. Extending along-the row l13 is a bams vided with a cross bams 15,as usual, the ames being arranged so that the gases flow across theentire length of thev lowermost rows of tubes and then backend forthacross the remainder of the tubes toa gas outlet. v The lowermost rowsof tubes, 'particularly the row 12, being subjected to the direct heatof the furnace, such tubes may be'hlistered.

1t, from the end of whiehextends upwardlya vertical bae 141, the boileralso bein proerably'ot the same thickness as thethic tubes arereplacedvtrom time to time this increased pressure tends to enlarge thehole .and nally makes it impossible to expand a tube properly in it.

By my' invention., l overcome this diculty by providing a thin-walledend portion in a @t tube having walls thicker than usual, this thinningofthewalls being done from the inside of' the tube. v Consequently, theexterior diameter of t-he tube before the ends are expanded is the samethroughout its length, the

internal diameter at the ends being larger for a short distance fromeach end than the injernal diameter o'fthe main portion of the tu e.

ln Fig. 2, l have shown one oit the tubes 1,2 'Elo expanded into aheader 10, the tube having a thin-walled section from its end to thepoint 1 6 and thev end of the tube having been expanded intothe tubehole in the header.

ln Figi 3,.the e'ect on this thin-walled tti section produced byexpanding the end'into the header is illustrated. lin vthisview theexpanding ytool 'l has been operated until its rollers R have expandedthe end of the tube as' shown in the drawing, thethin-walled secen tionextending far-enough beyond the front face of the header 10 'togivespace for the actionotthese'rollers on either side ot the wall of theheader. l

In practice, l'prefer to make all of the as tubes of the boiler of thesame external diameter and to have 'some only of the'tubes having the4two-internal--diameter construction. For instance, in the arrangementshown, the row of tubes 12` is the only one ce havingthick walls, andyet the external diameter of these tubes is the saine as that of. theremainder ofthe tubes in the boiler.

The thickness ofthe wall of the thin-end portion offthe thick-walledtubes is Ipre-'a nessl ofthe walls of the remaining tubes lof theboiler. Consequently,ithe effect in expanding the ends ot thesethick-walled tubes into the headeris exactll the same as it the tube ichhad vthe normal thic ess of wall, and, at the same time, .by havingthethick-walled portion, the life of the tube is greatly increased and itstendency to blister reduced.

By keeping the external diameter oit the 10a tube substantially uniformA throughout its length and making the variations in the thickness of.the wall by changes in the internal y diameter, the tube may be enteredand Withdrawn from the tube holes inthe headers end portions with vvallsthinner than the Walls ci the remaining portions of such tubes,

and others oifthe tubes having a substantially uniform vvall thicknessthroughout which is less than that ot the body portions ol the tubeshaving thinned end portions, the

exterior diameters ol all portions ol the tubes being substantiallyuniform throughout their length, and all ol' the tubeshavingsubstantially the same external diameter'.

r2. ln a vvater tube boiler, a vvater chamber Y having a plurality oiWater tube holes therein, all oithe holes being ol the same diame-` ter,and Water tubes, all ol said tubes having the same external diameterthroughout their` length and some ol said' tubes having an in tegral endport'on ol substantlally't e same externalv diameter as the main bodyportion oit the tube, but oi less thickness than the said main bodyportion, and others ol said .tubes having a Wall thiclniesssubstantially uniformy throughout but less than that ol the bodyportions of those tubes having thinned Y ends, all ol said tubes beingexpanded at wtheir ends in the holes in said vvater chamer.,

'3. ln a Wat/er tube boiler, a vvater chamber having a plurality olEvvater tube holes therein, all ol the holes being oil the same diameter,and vvater tubes, all ol said tubes having the same external diameterand some oil said tubes each having an integral end portion olsubstantially the same external diameter as the main body portion ol thetube, but oil less thickness than the said main body portion, said endportion being expanded in one oi said tube holes, the relatively 'thinvvall ol said lastnamed tubes extending -lrom the end el the tube te apoint spaced trom the neoaeo'a oiiter surface of said waterl chamber,and others of said tubes havig a Wall thiclmess substantiall uniformthroughout but less than that o the body portions of those tubes havingthinned ends, allof .said tubes being expanded at their ends in theholes in said vvater chamber.

4. ln a Water-tube boiler, a Water chamber a Wall of which is providedwith a hole, and a boiler tube having an integral `end portion otsubstantially' the same external diameter as the main body portion ofthe tube, but with its Walls oi less thickness than the thickness olsaid main body portion, said end portion being expanded in the hole insaid Wall.

5. ln al Water-tube boiler, viator chambers and ivater tubes connectedto said chambers with their ends expanded into the walls ol thechambers, certain of Vsaid tubes having end portions vvitli lvvallsthinner than the Walls of the remaining portions el such tubes, andothers ol the tubes having a substantially uniform Wall thicknessthroughout Whichis less than that of the body portions of the tubeshaving thinned end portions,`the exterior diameters oit all portions elthe tubes being substantiall uniform throughout their length, and all othe tubes havingsubstantially the same external diameter,.an d the endsoi those tubes with 4thinned ends having substantially the same Wallthiclmess as the `walls of those tubes having a substantially uniformWall thickness.

6. ln a Water-tube boiler, a Water chamber a wall ot vvhich is providedwith a hole, and a boiler tube having an integral end portion adapted tobe expandedinthe hole in said wall ot substantiall the's'aine externaldiameter as the main bo y. portion ol the tube, but

with its Walls of less thickness than the thiclri ness ol said main bodyortion.. Y

7. ln a Water tube boi er, a vvater chamber a vvall ol' which isprovided with a hola,` and a boiler tube having an. integral end portionadapted to be expanded in the hole in said Wall of substantially thesame external diameter as themain body portion et the tube, but vvithits walls of less thickness than the thicliness ot said main bodyportion, the relatively thin Wall ol said tube extending from the end etthe tube to a point spaced from the outer surface ol said vvaterchamber.

isaae interna lllll

